About the job
About Us
1GLOBAL is an innovative technology leader in mobile communications, offering unparalleled global connectivity solutions for both enterprises and consumers. Our cutting-edge telecom platform features a robust, owned global mobile core network, state-of-the-art in-house developed eSIM technology, and a wide array of telecom licenses, allowing us to operate as a fully regulated telecommunications provider in 40 countries around the globe.
We proudly serve some of the world’s most prominent banks, enterprises, and digital-first businesses, including neo-banks, global FMCG leaders, travel industry giants, and payment service providers. Currently, we empower over 70 million people and devices worldwide, facilitating our clients to launch, scale, and innovate confidently within the mobile ecosystem.
1GLOBAL is a rapidly growing, profitable entity, projecting full-year revenues exceeding US$200 million and profits over US$25 million by 2025. Our robust cash flow supports continuous investments in infrastructure, platform innovation, and global expansion. Recent years have been pivotal for us, marked by significant enterprise and consumer client acquisitions that enhance our status as a formidable global mobile connectivity provider, dedicated to helping consumer brands thrive in telecommunications.
Founded in 2022 by seasoned technology entrepreneurs Hakan Koç and Pyrros Koussios, 1GLOBAL is at the forefront of shaping the future of global telecommunications. We operate as a fully regulated Mobile Virtual Network Operator (MVNO) in 12 countries and as a regulated telecom operator in an additional 28 markets. Headquartered in the Netherlands, with premier R&D centers in Lisbon, Berlin, and São Paulo, our team of nearly 500 experts across 15 countries is unified by a singular mission: to redefine global mobile connectivity through unparalleled technology, scale, and operational excellence.
About the Team
This senior, hands-on Java position focuses on scalable backend systems, long-term ownership, and addressing real-world production challenges. You will be part of a newly formed backend team in Warsaw, dedicated to advancing our eSIM, global connectivity platform, and IoT solutions.
The role entails:
- Enhancing and modernizing existing systems,
- Developing new services and greenfield components,
- Boosting reliability, performance, and maintainability across the platform.
As a senior engineer, you will also lead the evolution of testing methodologies as systems evolve.

